Method to open a tetrahedron shaped container and device for carrying out said method



May 5, 1970 E R. BAJULAZ METHOD TO OPEN A TETRAHEDRON SHAPED CONTAINER AND DEVICE FOR CARRYING OUT SAID METHOD Filed Feb 15 1966 FIG. 2

Avmwme United States Patent Oflice 3,509,625 Patented May 5, 1970 3 509,625 METHOD TO OPEN A TETRAHEDRON SHAPED CONTAINER AND DEVICE FOR CARRYING OUT SAID METHOD Roger Bajulaz, Genthod-Geneva, Switzerland, assignor to Roger Bajulaz S.A., Genthod-Geneva, Switzerland, a corporation of Switzerland Filed Feb. 15, 1966, Ser. No. 527,684 Claims priority, application Switzerland, Mar. 15, 1965, 3,584/65 Int. Cl. B67d 7/30 US. Cl. 30-2 4 Claims ABSTRACT OF THE DISCLOSURE An apex of a paper container for liquids can be cut off by insertion in a pair of telescoping tubes the outer of which has an inclined cutting edge intermediate its length and the inner of which has its internal end formed as a cutting edge of opposite inclination. The cutting edges have a nonrectilinear contour such that when the apex of a paper container is inserted between the cutting edges and the tubular members are pressed together, the apex will be cut off so that the line of cut intersects the edge over which the liquid will be poured, at an angle greater than 45, thereby to facilitate pouring.

Up-to-now the most-widely-used container having a tetrahedron shape is used for milk, cream and so on. These containers are very practical for the sales organisations because the containers are disposable and inexpensive, whereby the cleaning and sterilisation processes necessary for returnable containers are eliminated.

n the other hand, these containers are somewhat less practical for the user. Users are usually advised to open a tetrahedron-shaped container by cutting ofi? one of its corners or apices along a straight line by means of sci-ssors. A container opened in this way is not properly adapted to have its contents poured out. When such a straight-cut corner is opened out the edges of the opening obtained in this way present a closed curve flattened along a line joining a seamed edge of the container and a folded edge of the container.

Seen from the front, this opening presents a point or tip which is downwardly directed and aligned with the fold.

Such an opening is very bad for the following reasons:

(a) The folded edge of the container is weakened along the line of fold. When it is desired to pour out the contents of the container by holding it by its seamed edge, as it is usually done, the container tends to fold even further, under the action of its own weight, along the line of fold. This reduces the size of the opening. Furthermore, because of this folding of the container, the volume of the container is diminished, which tends to raise the level of the liquid in the container, causing a total blocking of the opening by the liquid. This tends to cause uncontrolled pouring of the liquid, which emerges in intermittent jets which are with difliculty directed into a cup or like receptacle.

(b) The angle of the pourer point or lip of the opening, when the cut is opened out, is an obtuse one. This leads to liquid flowing along the outer wall of the container, which is most undesirable.

The present invention aims at overcoming these above disadvantages.

The present invention will now be described, by way of example, with reference to the accompanying drawing, in which:

FIG. 1 shows schematically opening a tetrahedronshaped container by cutting off one of its corners or apioes along a straight line;

FIG. 2 shows in front view the opening obtained by the cut shown in FIG. 1;

FIG. 3 shows in side view the opening shown in FIG. 2;

FIG. 4 shows diagrammatically an opening obtained according to the invention;

FIG. 5 shows in front view the opening shown in FIG. 4;

FIGS. 6 to 8 show variants of openings made according to the invention;

FIG. 9 is a perspective view of one form of device according to the invention for making the openings shown in FIGS. 4 and 5;

FIG. 10 is a plan view of the device shown in FIG. 9, and

FIG. 11 is a side view showing the device of 'FIGS. 9 and 10 in working position on a container.

FIGS. 1 to 3 show clearly the serious disadvantages of the openings made in known manner and shape in tetrahedron-shaped containers.

The opening obtained by cutting off an apex along a straight line presents a point downwardly-inclined, whereas the remainder of the cut, seen from the side, forms an upwardly-directed convex curve. When holding a tetrahedron-shaped container at an angle (-FIG. 3) in order to pour out the liquid contained in it, the weight of it tends to close the sides of the opening. Further, the angle of the point is very unfavourable, being obtuse.

According to the present invention, in order to open a tetrahedron-shaped container one apex of the container is gripped so that it is flattened along a plane coplanar with the seamed edge of the container. Then the flattened apex is cut along a line which intersects the folded, flattened edge at an angle comprised between 45 and 135 to the line of fold. Preferably this angle is substantially equal to The other end of the line of cut may intersect either the seamed edge, or even the folded edge at a location nearer the apex.

In this way the shape of the portion of the opening produced by opening out the flattened apex, adjacent to the line of fold, is generally acute and so leads to controlled pouring from the container.

FIGS. 9 and 10 show a device according to the invention for opening tetrahedron-shaped containers. This device comprises means permitting the device to be positioned correctly with respect to a flattened apex of a container to be opened, and cutting means enabling the flattened apex to be cut as desired.

The device shown comprises two parts 1, 2 sliding one within the other. The first part 1 presents, seen in side view, the general shape of a sector of a circle. It comprises two walls 3, 4 forming a right angle between them,

the two remote edges of which are connected together by a curved wall 5 which is concave towards the adjacent ends of the walls 3, 4. This curved wall 5 presents in the embodiment shown the shape of an arc of a circle the centre of which is located on the line of intersection of the walls 3 and 4.

Each of these plane walls constitutes a positioning member of the device. When a container is fully inserted into the device the straight edges a and b of the flattened apex come into contact with the inner faces of the walls 3 and 4.

An opening 6 is provided in the curved wall 5 to give passage to the flattened apex of the container. This opening extends from adjacent the corner of walls 3 and 5 to adjacent that corner of Walls 4 and 5. In the example shown this opening is slightly tapered so that the developed form of the opening is frustoconical, and the central axis of the opening is perpendicular to the longitudinal axis of the device. One edge 7 of the opening 6 constitutes one of the cutting edges of the device.

The part 1 comprises two flanges 8 and 9 folded at right angles with respect to the walls 3 and 4.

This part also comprises an abutment constituted by a lug 10 on wall 4 at its end remote from the flanges, and in the vicinity of the wall 3, which lug is slightly folded towards the inside of the part 1.

The second part 2 slides freely inside the first part 1 and presents thus a complementary cross-section to that of part 1, the outside dimensions of the part 2 corresponding to the inside dimensions of the part 1.

The length of part 2 is less than that of part 1 but is greater than the distance 1 separating the edge of the first part remote from the flanges from that point of the cutting edge 7 which is furthest away from the said edge.

This second part also comprises two plane walls 11, 12 which intersect at right angles, and the remote edges of which are connected by means of a curved wall 13, each of the walls 11, 12 and 13 being in sliding contact with the walls 3, 4 and 5.

This second part 2 comprises a second cutting edge 14 constituted by the leading edge of the wall 13 and intended to co-operate with the cutting edge 7 for cutting an opening in a tetrahedron-shaped container. In the embodiment shown, this/second cutting edge is slightly inclined with respect to the axis of the opening 6, and in a direction opposite to that of edge 7.

This second part 2 is also provided with flanges 15, 16 disposed at right angles with respect to the walls 11, 12.

This second part comprises a groove 17 in the inside of which is located the abutment 10 of the first part, that groove extending for a part of the length of the second part. The length of this groove 17 is at least sufiicient to enable the second part to be withdrawn from the first part 1 for a distance which is suflicient to free the opening 6.

The operation of the device is as follows:

The user moves the flanges 8, 9 and 15, 16 apart so as to slide the second piece 2 out of the first piece 1 until the abutment 10 comes into contact with the end of the groove 17 in the wall 12.

The user then grips the apex S of a tetrahedron-shaped container so that its sides adjacent to the apex become flattened against each other. In this way the apex S of the container is flat and presents an angle of 90.

The user then places the device on the flattened apex by introducing the apex in the opening 6, until the edge a and the line of fold b bear against the walls 4 and 3 respectively (FIG. 11).

After this the user moves the flanges 8, 9 15, 16 together to introduce the second part 2 further into the first part .1. The apex S of the container is cut off between the cutting edges 7 and 14 during this relative movement of the first and second parts.

Due to the weight of the liquid in the container it reassumes its normal shape again and the cut edges open out to define the desired opening.

The main characteristic of this opening resides in the fact that the angle formed by it with the line of fold b is a right angle, which enables the contents of the container to be poured out easily. When the container is inclined in order to pour out its liquid, the force due to the Weight of the liquid acts approximately along the direction f, which is tangential to the seamed edge a of the container. This removes or reduces any tendency of the edges of the opening to come together under the action of the weight of the container.

Numerous variants of the device can be made without departing from the scope of the invention.

All that is necessary to obtain an adequate opening of a tetrahedron-shaped container is for the folded edge of a flattened apex of the container to be cut at an angle which is greater than 45 to line b. This condition can be satisfied by a cut which again intersects line b but at a point nearer the actual apex.

The cutting edge of the device may present any shape which makes a cut satisfying this condition. The remainder of the cut may be a zig-zag line, a smooth curve, or a sinuous line, provided the opening does not extend to deeply into the container that it reaches the surface of the liquid in the container.

FIGS. 6 and 7 show shapes of cut edge which are possible and permit the obtaining of openings which are adequate. The shape of the cutting edges is varied accordingly.

FIG. 8 shows a variant in which the opening is formed of two parts, one part 18 to pour out the liquid, and the other part 19 for the introduction of air into the container to replace the poured-out liquid. This opening is readily obtained with a cutting device of the present invention. The shape of part 19 of this opening may be greatly varied and may be constituted by a perforation of the container which leaves the seamed edge a intact.

The present invention is not limited to the shapes of openings illustrated, or to the devices for producing these openings.

The main characteristic of the device for cutting off a flattened apex resides in the fact that it presents a cutting edge which is not straight. In fact, if the cut does intersect the line of fold at right angles, it is not possible to cut the container along a straight line as it would intersect the level of the liquid in the container. Thus the out has, after intersecting the folded edge, to extend upwardly towards the seamed edge of the container. Such a cut can only be obtained with a non-rectilinear cutting edge.

What we claim is:

1. A device for opening a tetrahedron-shaped container by cutting off an apex thereof, comprising means defining a pair of cooperative cutting edges which are movable relative to each other to cut off a flattened apex, which is bounded by a seamed edge contiguous with a folded edge, in them in a container is not a straight line and intersects an edge of a container at an angle greater than 45", said means defining said cutting edges comprising two members which are slidable relative to each other one within the other, one said cutting edge being formed by one edge of a longitudinally extending aperture in a curved wall of the outer member, the inner member being slidable in a direction transverse to the length of the aperture and having its leading edge formed as a cutting edge.

2. A device as claimed in claim 1, in which the developed shape of the aperture is at least partly conical.

3. A device as claimed in claim 1, and means for positioning a flattened apex of the container in a desired position relative to said cutting edges, means defining at least one inner surface which is positioned so as to be contacted by at least one of the apex proper and a boundary edge of the apex when the apex is fully in position for being cut off, and means defining a second inner surface, both said inner surfaces being positioned to be contacted by a respective one of the boundary edges of the flattened apex when the apex is fully in position for being cut off.

4. A device as claimed in claim 1, and an abutment on References Cited UNITED FOREIGN PATENTS 1/ 1957 Sweden.

ROBERT C. RIORDON, Primary Examiner 5 G. F. GRAFEL,aAssistant Examiner STATES PATENTS Stevener 30-233 Ashenfelter 30-289 X 30229, 241, 233, 280

Winton 30-229 Maldonado 30-2 X 10 

